Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

To make a creature in Spore, export it to a 3d program, then send that to a 3d printing studio?

If so I think I figured out how I'm going to make my army. Does anyone know how to do this/has done it before?

It might be, but don't expect it to be cheap or look all too great. 3D printing services can be expensive.

3D printing of a bunch of custom figures at that scale and size is going to either a) look like crap or b) cost more than buying the boxes of models would.

Ouch... I've never done anything like it before and was curious.

How feasible would it be to print one Gargantuan Creature sized model?

It would likely cost far more than it would to just buy it on ebay.

3D printing isn't going to come close to what you see in GW models for another 5-10 years, and even the best, most expensive materials you can get things made from look "tiered" right now, and have tiny steps on them. You'd be better off buying models as is.

Really going to depend on where you're getting it done at, but generally speaking, here's a few sites that offer this service, to set what you can expect:

http://www.sculpteo.com/en/services/

http://www.shapeways.com/model/164604/figurine-quot-hana-quot-17cm.html?li=curatedproductGroup&materialId=6

(very slightly NSFW, I guess, but not really... more importantly, pay attention to the lack of detail on this figure, and note that it is 17cm tall...anything at 40K scale in plastic is going to be fairly scant on details)

http://www.shapeways.com/miniatures?li=home-miniatures

This is the sales page for the previously-mentioned site. You can actually dig through their Shop and "Make & Print" sections to estimate how much a job will cost to run.

Buying spools of plastic for extruded printing cost ~£30 per kilo.
Laser-type printers cost less for materials, but more to set up.